now, you're jack kennedy. >> reporter: vice president joe biden and republican challenger, paul ryan, delivered stark difference on domestic and foreign policy. including how to fix the economy. >> we're going in the wrong direction. look at where we are. the economy is barely limping along. >> it shouldn't be surprising for a guy who says 47% of the american people are unwilling to take responsibility for their own lives. they pay more effective tax than governor romney pays in his federal income tax. >> reporter: ryan went after president obama for his response to the u.s. consulate attack in libya. >> it took the president two weeks to acknowledge that this was a terrorist attack. >> reporter: while biden challenged ryan's proposed changes to medicare. >> you are jeopardizing the program. you're changing the program from a guaranteed benefit. >> reporter: it was a more heated back and forth than the first presidential debate. and biden often laughed at ryan's arguments. >> joe biden understood, tonight, he had to go back out there and do what president obama failed to do last week.